Physical Fundamentals

PSA-4 As one can see in a log P/T-diagram, desublimation of PA occurs if its partial pressure is below the triple point. Here, for collecting PA in solid phase a switch condenser is required. If its partial pressure is above the triple point, PA can be collected in liquid phase with a liquid condenser (pre-condenser) or again in solid phase with a switch condenser.

GEA Switch Condenser

Since the invention of the Switch Condenser in 1954 GEA has delivered about 1500 switch condensers worldwide. We have continuously developed the mechanical as well as the process design of the switch condensers. In particular, we have adapted the special designed fin tube system composed of rectangular fins to the newest requirement of the PA process, mainly to the increasing feedstock loading of the air. PSA 003

The most important process key figures of the newest switch condensers are:

❚ gas flow: max. 30,000 Nm³/h

❚ capacity: max. 10,000 kg PA/cycle

❚ efficiency: min. 99.5 %

❚ oX-loading: 100 g/(Nm³ air) and higher

PSA-05

The design philosophy of our switch condensers is the optimal use of the entire installed surface for collecting PA. For that reason, we have introduced three sections of fin tube systems with different designs and functions.

PSA-06

The main task of the High Density Section is collecting PA in a very compact form. The High Yield Section is not only for PA collecting but also for gas cooling. Finally, the High Efficiency Section has a special filter function for PA needles, what guarantees the very high efficiency of GEA switch condensers.